Magnetic sound powered telephone



Oct. 26, 1954 S. l. BERGER Filed July 9, 1952 ATTORNEYS Patented Oct. 26, 1954 UNITED y,S','IATES l PT 0 FFICE i l y i I -'2,692,918- y.' ,i if. MAGNETIG SOUNDPOWEBED TELEPHONE; i I' l SamuelI.Berger,Newark,N. I, lfllisatie July 9, 1952,fserfia1Nq.-g97,s43 f This invention 'relates to telephonesy andmore particularly toa telephonie unit V'of the selfenergizing type that isadapted to' be used 'either for transmitting or receiving sound;`

It is among theobjects of the invention to provide a telephonic unit of the above type which is efficient in operation and provides a relatively high-delty response, yet ris"s'irnpleand corn'- pact in construction, light in weight, having but few relatively inexpensive 'parts f that vare not likely to become deranged and which aredesigned to facilitate mass'production assembly-to'form the complete unit at relatively'low cost. f A

According to the invention,A these: objects are accomplished by the arrangement 'and combina|- tion of elementshereinafterdescribed and particularly recited in the claims. i f

In the accompanying drawings in which is shown one or more of various possible embodi-` ments of the several features of the invention,

Fig. 1 is a longitudinal sectional view of the unit, f f

Fig. 2 is a transversevsectional 'view-y thereof taken along line 2-2of Fig. 1, and f Fig. 3 is a plan view taken along line v3;-'3201' Fig.1. -f

Referring now to the drawings, the telephonie unit desirably comprises a substantially rectangular base plate II of any suitable non-magnetic material such as brass, copper or plastic, the base plate II being of copper in the illustrative embodiment herein shown. 1 f -f The base plate II adjacent the edge I2 thereof desirably has a plurality of outstanding lugs I3, I4 and I5 integral therewith and vpreferably struck out therefrom between'which is positioned one end of a substantially L-shaped pole piece I6 of magnetic material such as steel. As shown in Fig. '1, the lugs I4 and I5 straddle thesides of leg Il of the pole piece I6 and the lugv I3uis against the end edge thereof, said lugs beingof such length as to rise above `|the top surface of said leg I7. -I v In order that the pole piecev I6 may .befproperly positioned on the base plate II andiref strained from longitudinal or transverse movement with respect thereto, the undersurface of leg I'l of the pole piece I6 desirably has `apair of bosses I8 protruding therefrom'which maybe positioned in complementary openings I9 in the base plate II. j'

As shown in Fig. 1, a pair of spaced parallel brackets 2| and 22, also of non-magnetic mate-l rial such as copper, are mounted on the base plate II extending transversely across the legv I1 l.9 claims.,l (01.179-102) t i of-pole piece lI6, one'of said brackets, i; e.; bracket 2l being'against the upturned leg I23 of fsaid pole piece I6. Althoughthe brackets' 2 I' and 22 'may be' mountediini anyI suitable manner, in the'illustrative embodiment -fherein shown, each" bracket has a rectangular `cutouty 24 vat -itsI bottomy edge deining 'a pair of-y legs `25 which straddle-the pole piece AI6 and extendv respectively through-#pairs of transversely aligned'- openings 26 lon each Xside thereof, thel brackets-.being secured finfplace as by twisting the end's'of legsy 25 which4 vprotrude beneath said baseplate -II." "-'1- f Positioned between-thebrackets -2I and 22fis=a coil'of lwire 29 which is desirably wound'around 'a tubular core 3l of-finsulatingmaterialfdesire ably substantially rectangular in cross .section- The core'3I desirably has a substantially rectan.- gular plate 32 of insulating material at each end thereof with a rectangular slotA therein in which the respective ends-of the core vmay be axed, the end plates desirably tting snugly against the associated brackets 2| and 22. l Each of thebrackets has a slot 34 therethrough whichv are longitudinally alignedfwith/l respect to the leg vI'I of pole piece I,6..-A1ixed as by solder-i ing in the slot 34 in bracket 22 is'one end.,y of 'an armature reed 35 of magnetic: material preferably of steel whichds centrallyrpositioned inand ein tends through thecore 3'I-and,through the slot 34in bracket 2l andy protrudes as aty 36 past ythe upturnedleg- 23A-of pole piecel I6, said-.reed,3;`l beingslightly spaced from saidA leg 23to dei-ine anair gap therebetween. qq. i l' Positioned between the lugs I3, I4 and I5 and straddled thereby is a rectangular block magnet 38 preferably of -Alnico havingvv its north` pole, forA example,` restinglon the end ofvleg I1 of pole piecerI6. i Positioned against the other or south pole of magnet 38 isthe .endy of the ;leg,39..of

which extends parallel tothe leg, I'Iof polepiece I6 and has adownwardly extending leg ,4I which is aligned with leg 23 yof, pole pieceIG and is also spaced from the protruding end.3,6,of. armature reed 35 dening .fa-second air gap. therebetween, said `end. A36 being 'centrally' positioned between said: legs 23` and 4I. The` pole: ,piece 40 iwhich rests on the upper edges-of.c brackets 2| and'22 being positioned in longitudinally aligned notches A45 thereinllis Isecurely`retained1=in position by rneansof lugs 46 formedintegral withy the brack-` ets 2 Iy and 22?, which"l extend through complementaryy longitudinally 'aligned openings' 41' -in p01@ piece a9 and are bent overias aus. l

With the construction above described,` th'e lugs I3, I4 and I5 will prevent longitudinal or transverse displacement of the block magnet 38 and the pole piece 4B which is securely clamped in place against the brackets 2I, 22 will prevent vertical displacement of said block magnet 38.

The base plate II is desirably mounted on a panel 5I which carries a flexible diaphragm 53. Although the base plate II may be mounted in any suitable manner, in the embodiment herein shown, the panel 5I which preferably is of plastic has four outstanding studs 54 desirably arranged in a rectangle and tapering slightly toward the nose 55 thereof. The studs Sii are designed to t into complementary openings 56 near each corner of the rectangular base plate I I and the plate is affixed to the panel as by applying heat to the nose end 55 of the studs, the plate H thereby wedging on the tapering portion thereof.

The panel 5I on the outer surface thereof desirably has a circular cavity 58 with a central opening 6i) in the floor 59 thereof through which extends a drive rod affixed at one end as by soldering to the protruding end 36 of the armature reed 35. The other end of the drive rod 6I is affixed, also as by soldering, to diaphragm 53 which desirably is of metal and which is positioned at its periphery on an annular shoulder 62 formed about the periphery of said circular cavity Eii. Although the diaphragm 53 may be retained on said shoulder in any suitable manner, in the embodiment herein shown, an annular member 63 of cuter diameter substantially equal to that of the crcuiar cavity 5S is positioned in the latter and desirably cemented therein, the rim of said annular member clamping the periphery of said diaphragm E3 against said shoulder 62. Desirably a perforated disk 55 is affixed as by cementing to an inturned iiange 66 of annular member 63, said disk and said annular member functioning as the mouth piece and receiver of the telephonie unit.

When the telephonie unit is used as a receiver and a signal current is applied to the ends of coil 29 from the output of the coil of an identical unit (not shown), a force will be created to vibrate the armature reed thereby decreasing one of the air gaps between legs 23, 4I and armature reed 35, and increasing the other. Such movement of the armature reed will, through drive rod Si, eifect movement of the diaphragm 53 to produce an audible sound corresponding to that applied to the mouth piece of said other identical unit'.

When the unit is used as a microphone or transmitter, the diaphragm 53 will be vibrated by the sounds impressed thereon and such vibration will be transmitted through drive rod 6I to armature reed 35. The movement of the armature reed 35 will generate a signal voltage in the coil 29 which will be transmitted through suitable leads to the coil of the companion unit.

With the construction above described, a simple yet highly efficient telephonie unitv is provided, which may readily be assembled by mass production methods and which is neat and compact and may be used without need for any batteries when transmission of intelligence is desired for a short distance.

As many changes could be made in the above construction, and many apparently widely different embodiments of this invention could be made Without departing from the scope of the claims, it isintended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. A telephonie unit comprising a block of permanent magnet material, a pair of pole pieces each having one end against one of the respective poles of said magnet and extending in parallel paths away therefrom, said pole pieces having their other ends bent toward each other defining a gap therebetween, a pair of spaced parallel brackets extending transversely between said pole pieces, an armature strip affixed at one end to the bracket adjacent said magnet block and extending away therefrom parallel to said pole pieces past the other bracket and through the gap between the bent ends of the pole pieces, a coil surrounding said armature and positioned between said brackets, a diaphragm, a support for said diaphragm and a drive rod connecting said diaphragm to the free end of said armature.

2. A telephonie unit comprising a base plate of non-magnetic material, a substantially L-shaped pole piece on said base plate having one leg seated thereonand one leg bent outwardly therefrom at right angles thereto, a block of permanent magnet material having one pole positioned on the free end of the leg of the pole piece on said base plate, a second substantially L-shaped pole piece having the free end of one leg thereof on the other pole of the magnet and having an inwardly bent leg aligned with the outwardly bent leg of the first pole piece and spaced therefrom defining a gap therebetween, a pair ci' spaced parallel brackets extending transversely between said pole pieces and affixed to said base plate, an armature strip affixed at one end to the bracket adjacent said magnet block and extending away therefrom parallel to said pole pieces past the other bracket and through the gap between the bent ends of the pole pieces, a coil surrounding said armature and positioned between said brackets, a diaphragm, a support for said diaphragm and a drive rod connecting said diaphragm to the free end of said armature.

3. The combination set forth in claim 2 in which said base plate has a plurality of lugs rising therefrom and straddling the free end of the leg of the pole piece on said base plate.

4. The combination set forth in claim 2 in which said base plate has a plurality of lugs rising therefrom and straddling the free end of the leg of the pole piece on said base plate, said lugs extending beyond the upper surface of said leg, said magnet block being positioned between said extending portions of said lugs.

5. The combination set forth in claim 2 in which said base plate has a plurality of lugs rising therefrom and straddling the free end of the leg of the pole piece on said base plate, said base plate and said leg having complementary coacting conformations to restrict longitudinal and transverse movement of said pole piece on said base plate.

6. The combination set forth in claim 2 in which said base plate has a plurality of lugs rising therefrom and straddling the free end of the leg of the pole piece on said base plate and said leg has a plurality of bosses on the undersurface thereof which coact with complementary openings in said base plate to restrict longitudinal and transverse movement of said pole piece on said base plate. l

'7. A telephonie unit comprisingV a base plate of non-magnetic material, a substantially L- shaped pole piece on said base plate having one leg seated thereon and one leg bent outwardly therefrom at right angles thereto, a block or" permanent magnet material having one pole positioned on the free end of the leg of the pole piece on said base plate, a plurality of lugs rising from said base plate and straddling the free end of the leg of the pole piece on said base plate and the block magnet thereon, a pair of spaced parallel brackets extending transversely across the leg of said pole piece and axed to said base plate, a second substantially L-shaped pole piece having the free end of one leg thereof on the other pole of said block magnet and extending across the upper edges of said brackets, and having an inwardly bent leg aligned with the out- Wardly bent leg of the rst pole piece and spaced therefrom dening a gap therebetween, complementary means on the upper edges of said brackets and the leg of said second pole piece extending thereacross securely to retain said leg on said upper edges, thereby retaining said block magnet between said lugs, an armature strip affixed at one end to the bracket adjacent said magnet block and extending away therefrom parallel to said pole pieces past the other bracket and through the gap between the bent ends of the pole pieces, a coil surrounding said armature and positioned between said brackets, a diaphragm, a support for said diaphragm and a drive rod connecting said diaphragm to the free end of said armature.

8. The combination set forth in claim 7 in which the support for said diaphragm comprises a panel having a circular cavity in the front face thereof with an annular shoulder on which the periphery of the diaphragm is seated, means clamping said diaphragm on said shoulder supporting means on the rear face of said panel for said base plate, said cavity having an opening in the floor thereof through which said drive rod extends.

9. The combination set forth in claim 7 in which the means to retain the leg of the pole piece on the upper edges of said bracket comprises a lug formed integral with each of said edges and extending through complementary openings in said leg.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 2,245,511 Turnbull, Jr., et al. June 19, 1941 2,400,281 Anderson May 14, 1946 2,454,425 Bauer Nov. 23, 1948 2,523,775 Muldoon Sept. 26, 1950 2,536,179 Heller Jan. 2, 1951 2,582,942 Baker Jan. 22, 1952 

